It looks like this file is corrupted. I tried to duplicate your file and it is damaged as well. You cannot select tools, nor can you change the background of the canvas, because the Design panel doesnβt have this field.
Not sure if restoring from Version History will help you, but you can try. More details on how to recover from the File Browser here: https://help.figma.com/hc/en-us/articles/360038006754-View-a-file-s-version-history#Restore_from_version
Also send a bug report to support using this link: https://help.figma.com/hc/en-us/requests/new?ticket_form_id=360001744374
Fortunately, I contacted Pigma and solved it. The cause was that the memory of this file was exceeded and all buttons and commands on the page, including version history, did not respond.
If you have the same symptoms, you can open the fileβs version history through a preview in the file browser.
Thank you for your kind answer. Fortunately, we solved the problem. Thank you!